CO elites have better award inventory on CO and same inventory on NW as NW elites. NW elites do NOT have availability to CO's elite award inventory.

Asia award structure is different. Less miles from GUM to NRT on NW. More miles on NW from GUM to CNS. Careful.

NW gold/plat get upgraded on domestic award tickets. No upgrades on CO award flights.

Redeposit fees are different, or at least have been. More for NW in past.

No longer will be able to Hold NW awards for 2-3 weeks. Can hold with CO.

Dedicated elite line with NW.

No change fee or something similar NW awards when done online. Don't believe that CO will have same type of "no fee" options.

....jl2